Shishosei
Summary
After with the sudden and mysterious death of the youth who was to be selected as the next king, the Library Tower, which housed all the books of the country, was sealed off. However, deep in the recesses of the tower, where no one should have been able to enter, sat the one who was known as the Chief Librarian (Shisosei). In the palace where rumors flutter about, conspiracies begin to swirl. What is the astonishing reality behind the connection of the youth's death, the Library Tower, and the country's secret tool, the Chief Librarian?
... and the second season of the Anime did a better job of pacing than I thought they would. I think they moved the Elf village arc from before hostilities with the Principality began to the inter-war period, aka the start of the second season, and used that to pad it out. Good call if that's what they did. In any event. Good season.